71How to operate the tunerFM reception characteristicsA characteristic of transmitted signals is that lower frequencies travelfurther. FM frequencies are much higher than AM’s (similar to a ray oflight): they won’t bend but they will reflect. Often, they will beinterrupted by tall buildings, mountains, etc., taking direct and indirectpaths to your vehicle’s antenna. The distance at which FM stations canbe received satisfactorily is usually not nearly as far as that which AMstations can be received.In weak signal or “fringe” reception areas, FM stations may fade outcompletely, or fade in and out. When driving in weak signal areas, suchas near hills, through valleys or tunnels, among tall buildings, etc., youmay encounter unusual noise interference. THIS IS NOT A TUNERPROBLEM. In this case, you can only wait until you are in a betterreception area, tune to a stronger station, or reduce the treble level.In general, FM has much better tonal quality than AM. However, FM and FMstereo reception encounter several characteristic problems not encounteredwith AM. FM is more difficult to receive than AM in a moving vehicle. Thefollowing are explanatory notes on what to expect from FM reception and onhow to get satisfactory performance.Ionosphere IonosphereAM Radio Waves FM Radio WavesFM RECEPTION DIFFERS FROM AMFADING OUT
